d and d造句

• The software defined radio is a new kind of concept and system that is putted forward in recently years to realize the communication , and is applied to wireless communication . its core lies that : the converter of the broad band a / d and d / a should be made close to the antenna as possible as it can
  软件无线电是近几年来提出的一种通信新技术，目前主要应用在无线通信领域。它的核心是：将宽带a d和d a变换器尽可能地靠近天线，而电台功能尽可能地采用软件进行定义。
• The paper is completed research of measurement and control system based on dsp under technology . the paper is designed a card with the data - collection conversion and control by adopting mainly tms320f240 among the dsps as kernel processor , with peripheric a / d and d / a circuit epm7128 ' s decode and latch circuit and isa interface circuit
  本论文主要是采用数字信号处理器dsp中的tms320f240作为核心处理器，结合外部的模数转换和数模转换电路、可编程逻辑器件epm7128的地址译码和锁存电路和isa接口电路，设计了集采集、转换、控制于一身的isa卡。
• His idea is based on the fact that the pivot of the soft wireless structure is to put the broad band a / d and d / a conversion near to antenna by all means , and to define the functions of the transmitter - receiver as many as possible in the forms of software ( namely realized by software ) . the technology of background signal simulator puts the focus on the methods used to realize the software , namely to exploit the functions of the hardware ( for example , dsp fpga or asic ) through the idea of software design , and to produce ( realize ) wireless signals by high speed lsi and software programming
  1992年5月的全美电信系统年会上， mitre公司的资深科学家joemitola首次给出了软件无线电的定义，他认为：软件无线电的组成架构的中心点是将宽带模?数( a d )和数?模( d a )转换器尽可能地靠近天线，将尽可能多的电台功能以软件的形式定义(即用软件来实现) 。背景信号模拟器所采用的技术集中体现在软件无线电技术，即用软件化设计去开发硬件(如dsp 、 fpga 、 asic )功能，采用高速大规模数字集成电路、软件编程的方法产生(实现)各种无线电信号。
• The whole architecture of software radio system is divided into five modules including wide band antenna and radiant frequency front - end module , wide band a / d and d / a one , converter one , digital signal processing one with high speed and instruction processing one . accordingly some technical nodi are analyzed and key techniques to solve these questions are stated in the every module at length . during the software design , the modularization design of the software radio is accomplished with borland c + + builder and the main module program is written so that the system can work in three different ways such as receiver , transmitter and gateway
  本文跟踪国内外软件无线电最新研究现状，详细推导了软件无线电的基本理论；在方案论证的基础上，把pc机、 windows操作系统分别作为通用硬、软件平台，将软件无线电系统在结构上分为五个模块，分别为宽带天线及射频前端模块、宽带模数和数模转换模块、变频器模块、高速数字信号处理模块和信令处理模块，并对每个模块中的技术难点和实现此模块功能的关键技术进行详细论述；在系统软件化设计过程中，利用borlandc + + builder完成软件无线电系统总体模块化设计，编写了主模块程序，使整个系统能工作于三种状态：接收机、发射机和网关。
• The software radio is one of the new communication systems which were presented in recent years . the fundamental idea of software radio is to establish an open , standard and modular universal hardware platform where the a / d and d / a converter is moved as close as possible to antenna and all of the communication function is realized by software . the aim is to research and develop a high flexible and adaptable communication system
  软件无线电是在无线电通信领域提出的一种新的通信系统体系结构,它的基本思想是构造一个具有开放性、标准化和模块化的通用硬件平台,将宽带a / d和d / a转换器尽可能靠近天线,通过软件编程来实现各种功能,以研制出具有高度灵活性和适应性的无线通信系统。
• The theoretical analysis and simulate results show that the chaotic adc proposed in this paper overcomes the problems of the gain mismatches between stages and the mismatches between a / d and d / a in single stage in the pipeline adc , which severely infect the resolution of adc , and this kind of adc also be not sensitive to noises so that the precision requirements of some components used for the system are much easier to be achieved . therefore , using this approach we may achieve a conversion at high speed and high resolution
  理论分析和实验仿真表明本文所提出的a / d转换器克服了流水结构a / d转换器多级之间的增益匹配和每级中a / d和d / a转换之间的匹配等主要影响精度的设计问题，具有对噪声干扰不敏感等特性，降低了对部分元器件的精度等要求，可能为高速高精度a / d转换器的设计提供一种新的途经。